Nagios upgrade issue

From Wiki

Again, the problem was that old configs were kept, rather than installing the new version. The problem was:

server:~# /etc/init.d/nagios start
Starting nagios monitoring daemon: nagios
Nagios 1.4
Copyright (c) 1999-2006 Ethan Galstad (nagios@nagios.org)
Last Modified: 05-03-2006
License: GPL
Reading configuration data...
Error: Command 'check-fast-alive' has already been defined
Error: Could not register command (config file '/etc/nagios-plugins/config/ping.cfg', line 37)
***> One or more problems was encountered while processing the config files...
Check your configuration file(s) to ensure that they contain valid
directives and data defintions. If you are upgrading from a previous
version of Nagios, you should be aware that some variables/definitions
may have been removed or modified in this version. Make sure to read
the HTML documentation on the main and host config files, as well as the
'Whats New' section to find out what has changed.
errors in config!
failed!

Solution:
In /etc/nagios-plugins/config/ there was ping.cfg and ping.cfg.ucf-dist. The latter was the most recent config. The difference between the two was the extra piece on check-fast-alive. It had to be removed from ping.cfg and then nagios started fine.